The error message means that your system is running low on memory. I'm not sure if it's related to the theme or any plugin in particular, as this usually happens when the number of plugins get higher.
– Disabling any plugin that you might not need to decrease the load
– Checking the memory limit in your php.ini to see if it's around 256M
You could also try to increase the memory limit by editing the wp-config.php file, by adding the following line:
just before this line (almost at the end of the file):
/* That's all, stop editing! Happy blogging. */
Let's hope that helps!Best,
If you like my products, don't forget to rate them on codecanyon :)